Alert archive / Montana / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 21, NWS Great Falls, MT

July 1, 2001Pondera County, Montana

NWS Great Falls, MT issued this severe thunderstorm warning at Jul 1, 2001, 4:06 AM MDT for Pondera County, Montana. It was in force for 24 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued
Jul 1, 2001, 4:06 AM MDT (10:06 UTC)
Expired
Jul 1, 2001, 4:30 AM MDT
In force
24 min
Issued by
NWS Great Falls, MT
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Pondera County, MT

The radar

The Great Falls radar (KTFX), 109 km from the middle of the area, began a volume at 10:06 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Jul 1, 4:12 AM MDTThunderstorm Wind 52 EValier, MTReported by spotter in Valier.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Great_falls, MT (KTFX), launched 00:00Z, 10.1 hours before the alert went out and 150 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Great_falls, MT at 00:00Z on 2001-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 63 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Great_falls, MT at 00:00Z on 2001-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 94 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
63 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
1726 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
94 m²/s²
0-3 km storm-relative helicity
312 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS55 KTFX 011007
SVRGTF

MTC073-011030-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREAT FALLS MT
406 AM MDT SUN JUL 1 2001

THE NATIONAL WEATHER SERVICE IN GREAT FALLS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL PONDERA COUNTY IN NORTH CENTRAL MONTANA
  THIS INCLUDES THE CITY OF CONRAD

* UNTIL 430 AM MDT

* AT 404 AM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 7 MILES SOUTHWEST OF VALIER...OR ABOUT 20 MILES
  WEST OF CONRAD...MOVING EAST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  4 MILES NORTH OF CONRAD AT 430 AM MDT

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGEN'CY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN GREAT FALLS.

LAT...LON 4835 11252 4816 11237 4815 11178 4832 11189

The office that day

Everything else NWS Great Falls, MT issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 3:00 AM MDTSevere Thunderstorm WarningTFXGlacier, Pondera30 min
Jul 1, 4:34 AM MDTSevere Thunderstorm WarningTFXPondera, Toole41 min
Jul 1, 7:49 AM MDTSevere Thunderstorm WarningTFXBlaine26 min

Nearby

Severe Thunderstorm Warnings in Montana, 2001Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.